Timing jitter in dispersion-managed soliton systems with distributed, lumped, and hybrid amplification

Abstract

Abstract-We analyze the role of distributed amplification in controlling timing jitter in dispersion-managed soliton systems and discuss, using analytical and numerical techniques, how timing jitter is reduced by up to a factor of two when lumped amplification is replaced by complete or partial distributed amplification. We derive an analytical expression for the timing jitter at any position within the fiber link in the case of ideal distributed amplification for which losses are exactly compensated by gain at every point. We show that the timing jitter is well approximated by this formula in the case of erbium-based amplification. We derive a similar expression for the timing jitter for lumped amplifiers and compare it with the case of distributed amplification. We find that with erbium-based distributed amplification, timing jitter depends on the density of dopants and is smaller for lower densities. In the case of hybrid Raman amplification, the transmission distance of a 40-Gb/s system can be increased by up to 30% depending on the amount of Raman gain. Finally, we show that timing jitter decreases for stronger maps at a given bit rate (constant minimum pulsewidth).

High Bit Rate Dense Dispersion Managed Optical Communication Systems With Distributed Amplification

“…The resulting noise due to distributed amplification under such cases is also small. It is well documented [29] that bi-directional pumping causes small timing jitter. In fact, timing jitter in a DM system with distributed amplification and bi-directional pumping is not significantly different from the timing jitter caused in ideal distributed amplification for which losses are compensated by gain at every point.…”

“…(15)- (18). This simplification is usual and has been employed in many important investigations [29].…”

Investigations on optical timing jitter in dispersion managed higher order soliton system

“…10) are produced by keeping the parameters as shown by case-II of Table 2. Optimum amplifier spacing has been studied so far is for data formats namely RZ, soliton but for higher order solitons it is investigated and reported further [4,5,18,19]. Here, amplifier spacing related parameters are set so that optical signal level in the fibers remains same to avoid excitation of other nonlinearities.…”

“…In modern long haul fiber optical communication links, Gordon Haus (GH) timing jitter arising as a result of amplified spontaneous emission (ASE) is one of the major limiting factors at higher data rates [1][2][3][4][5][6][7][8][9]. In the past, various analytical techniques perturbation, linearization Schrodinger equation, variational method, have been devised to model timing jitter in constant dispersion, dispersion-decreasing and dispersion managed (DM) optical communications systems [1,3].…”

“…It has also shown us the effect of typical second order and third order dispersion terms on the growth of timing jitter [18]. Further, distributed amplification in place of lumped amplifiers for uniform-dispersion, dispersion decreasing and dipersionmanaged fibers, for Chirped Return to Zero (CRZ) format based systems has been proposed to tackle timing jitter problem [4][5][6][7]. Analytical, as well as numerical simulation techniques have been used to find the optimum extent of pre-, post-dispersion compensation to control timing jitter [3,8,9].…”